Well look at the question.
It is asking you the total difference between the winners score to their opponents score in the contest.
Going by how the graph looks, approximately:
Javi's scores are 10, 20, 60, 20, and 15.
MeriAnne's scores are approximately 20, 30, 40, 20, and 10.
Add all those numbers up individually for each contestant.
Javi has a total score of 125.
Meri has a total score of 120.
Subtract the total scores from each other, as so:
125 - 120 = 5.
Javi read 5 more pages than Meri.